JP2001170215A - Soft tennis ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inject air into a soft tennis ball by using an air injecting jig having a round front end and to surely prevent the air leakage from a communicating hole for insertion of this jig. SOLUTION: At one part of the ball 1 is provided with an air injection valve mechanism 3. The air injection valve mechanism 3 is provided with a rubber plug which is fixed to the spherical shell of the ball in the state of exposing its one end to the ball surface and projecting the other end into the ball and has insertion holes at both ends so as to allow the insertion of an insert rod 501 having a round front end from outside the ball to the inside of the ball and a one-way air permeable check valve 303 which is fitted into this rubber plug to cover another end hole 3022 of the insertion holes and permits the ventilation into the ball of the air injected by the air injecting jig 5 but obstructs the ventilation of the air in the ball into a hole port of the other end of the rubber plug.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a soft tennis ball, and more particularly to a mechanism for injecting air into the ball.

[0002]

2. Description of the Related Art A conventional air injecting mechanism for a soft tennis ball has a column-shaped rubber called so-called "navel" fixed to the inner surface of a ball shell, and a pointed tip for air injecting shown in FIG. A needle 701 of the injection needle type air injection jig 7 is pierced from the outside of the ball so as to penetrate the navel, and air is injected by compression of a rubber pump 702. After the injection, the needle 701 is removed and the contraction force of the rubber itself of the navel is removed. It is common to use a structure with no air leakage.

However, in such a soft tennis ball air injection mechanism, if the needle 701 is accidentally stabbed into a portion other than the navel, the ball itself does not have an air leakage function due to shrinkage after the needle is pulled out. There is a problem of causing a fatal defect that the ball becomes unusable. In addition, the injection needle type air injection jig has a problem that a person's hand or the like is accidentally stabbed. Therefore, it has been desired to employ an air injection jig which does not have such a fear.

From such a viewpoint, a proposal has been made in which a valve-type air injection mechanism employed in a basketball, a soccer ball, or the like is diverted to a soft tennis ball (JP-A-11-16).
No. 4913).

A general air injection mechanism employed in basketballs and the like is provided with a slit which communicates with the inside and outside of a rubber stopper so that a jig for air injection having a rounded tip can be inserted. Balls have an internal pressure of 40-100k
Since it is high as Pa, it is necessary to sufficiently prevent air leakage from this slit portion. Usually, a ring or the like that strongly tightens the slit is usually assembled to the inside of the ball of this rubber plug, and the soft tennis ball proposed above The air injection mechanism basically adopts the same configuration.

According to this method, since the work can be performed using a rod-shaped air injection jig having a round tip, the above-described disadvantage of the needle type air injection described above is solved.

[0007]

However, according to the study of the present inventor, it has been found that the method of applying the above-described structure of the air injection mechanism such as a basketball to a soft tennis ball has the following problems. . First, basketballs, soccer balls, and the like have a large diameter and a thick spherical shell, and have high shape retention properties that hardly deform as a whole, and the rubber stopper slit is tightened with a strong tightening force. However, the work of fitting a jig for air injection with a rounded tip into the slit of the rubber plug can be done so easily, but for a soft tennis ball with a small diameter and a soft spherical shell, a rubber plug that is tightly tightened On the other hand, the operation of fitting the jig for air injection is not always easy. Second, the internal pressure of the soft tennis ball is 3.0-
Since it is a very low pressure of 6.0 kPa, it seems that the tightening force for preventing air leakage may be smaller than that of a basketball or the like, but in fact, a soft tennis ball is greatly deformed by hitting, If the tightening force of the slit is weak, the plug may be insufficiently sealed, and air may leak from the slit when the ball is deformed. Third, the soft tennis ball is lightweight, and if the weight of the rubber plug increases, the center of gravity of the ball will be deviated, which may cause the flying ball to shake. It is desired to reduce the weight.

In view of the various problems as described above, a slit or the like is provided to insert a jig for air injection having a rounded tip into and out of the ball. Without strongly tightening
The study was repeated with the aim of preventing air leakage by a one-way breathable lightweight mechanism, and the structure of the soft tennis ball of the present invention was developed.

Another object of the present invention is to provide a novel structure in which a soft tennis ball provided with an air injection valve mechanism for allowing air injection using a jig having a rounded tip can be easily manufactured. Where you do it.

It is another object of the present invention to provide a soft tennis ball having a novel structure so that the navel portion can be easily found during an air injection operation.

[0011]

A soft tennis ball according to the present invention which achieves the above object is a soft tennis ball provided with an air injection valve mechanism for injecting air into the ball inside a part of a ball shell. The air injection valve mechanism is fixed to the ball shell with one end exposed to the surface of the ball shell and the other end protruding into the ball, and has a rod-shaped air from the outside of the ball to the inside of the ball. A rubber stopper having an insertion hole extending across the both ends so that the injection jig can be inserted, and the rubber stopper is fitted to the rubber stopper so as to cover the other end opening of the insertion hole, and is fitted and inserted into the insertion hole. And a one-way permeable valve member that prevents the air in the ball from flowing into the hole at the other end of the rubber plug, while allowing the air injected by the air injection jig to flow into the ball. It is characterized by having.

In the above structure, the rubber stopper forming a part of the air injection valve mechanism has a role as a member for forming the insertion hole, and at least a part of the insertion hole extending from the outside of the ball to the inside of the ball. Is preferably a slit-shaped insertion hole, and preferably, as in the invention of claim 5, a cylindrical portion at one end side (tip side) provided to be exposed and opened on the ball surface; It is preferable that the slit provided on the other end side (rear end side) inside the ball is continuous. By configuring the insertion hole in this manner, the opening of the cylindrical portion on the ball surface serves as a mark when inserting a jig for air injection with a round tip, and the cylindrical portion serves as a guide for inserting the jig, This is because the slit portion contributes to the function of preventing air leakage.

[0013] Further, the rubber stopper has a tip tapered (conical, wedge-shaped, etc.) toward one end (the end on the side exposed on the ball surface) as in the invention of claim 6. It is preferred that By providing in this manner, a rubber plug whose tip is provided in a tapered shape such as a wedge-like shape is attached to an unvulcanized ball shell forming member prepared for forming a ball shell of a soft tennis ball. Can be incorporated into the uncured ball shell forming member by pushing it from the inner surface to the outer surface of the ball shell, and after bonding and fixing, the ball ball shell is molded and vulcanized, and then the same ball as before By polishing the outer surface of the shell and shaving off the tip, the tip of the rubber plug can be exposed on the outer surface (surface) of the ball. This makes it easier to assemble the rubber plug and to facilitate the ball manufacturing operation. it can.

The one-way permeable valve member constituting another part of the valve mechanism is easily collapsed by the internal pressure of the ball and closely adhered to the other end of the rubber stopper as in the second aspect of the present invention. When air is injected by the air injection jig inserted into the insertion hole, a flexible film bag that expands to form a space near the other end is used, and a part of this bag is used. An example in which an opening for ventilation is provided to seal the gap between the opening at the other end of the rubber plug and the opening of the bag body by crushing the bag body can be exemplified. Further, as in the invention of claim 4, one end is provided in a circular opening shape (sleeve shape) fitted to the other end of the rubber stopper, and the other end is provided in a flat strip shape having a slit for air outflow. Can also be used.

[0015] Of these valve members, in the case of the former flexible film bag, a portion other than the opening provided in the bag is sealed with a rubber stopper so that the bag is made of a ball. When crushed by internal pressure, it can be tightly attached to the rubber stopper to prevent air leakage from the slit. In addition, it is preferable that the opening at the other end of the rubber stopper and the opening of the bag body are provided in a positional relationship such that they do not overlap when crushed, in order to more reliably prevent air leakage.

As a material of such a bag, for example,
Examples thereof include a plastic film and a rubber latex film having heat resistance enough to withstand the heat of vulcanizing the rubber of the ball spherical shell.

In the case of the latter, which is a flat strip-shaped valve member having one end on the sleeve side and the other end on the slit,
The structure of the valve member itself constitutes a valve having one-way air permeability (check valve). As a preferable shape of such a valve member, for example, the flat strips on both sides of the slit and both side edges of the strip are respectively connected to the sleeve-like portion via an arc-shaped surface concave outward. Things can be mentioned. This valve member can also be made of plastic, rubber or the like having the same heat resistance as described above.

The rubber stopper is not limited, but generally, natural rubber is preferably used, and a wedge-shaped front end portion, a rear end columnar portion, and a flange portion may be integrally formed. Alternatively, some or all of them may be separately formed and integrated by bonding. Specifically, it is also preferable that the tip portion and the flange portion are formed as a first part integrally formed, and this is bonded to and integrated with a separately formed columnar second portion.
The shape of the tip may be a shape suitable for the above-mentioned pressing, such as a conical shape, a shape combining a cone and a truncated cone, or a shape combining a cone and a columnar shape.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIGS. 1 to 6 show an embodiment of the present invention. A soft tennis ball 1 according to this embodiment is a ball which forms a rubber ball body as shown in FIG. It comprises a spherical shell 2 and a rubber plug 3 whose tip is exposed on a part of its surface (outer surface). In these figures, the height of the rubber stopper is exaggerated for convenience of explanation.

As shown in FIG. 1, the structure of the rubber plug 3 of the present embodiment has a substantially conical shape as a whole by changing the inclination angle at the angle change point 3012 in the middle of the slope so as to become gentle toward the tip. A vulcanized first part 301 integrally formed with a leading end portion 3011 and a disk-shaped flange portion 3013 extending radially outward from a conical skirt portion thereof, and a vulcanized member having a solid columnar shape. The second part 302 includes a sulfurized second part 302 and a check valve 303 (see FIGS. 1 and 2). The second part 302 is adhered and fixed via an adhesive concentrically with the flange part 3013, Further, the check valve 303 is configured to be fitted and fixed to the second portion 302 at the body portion 3031 thereof.
Reference numeral 3014 denotes a blind hole, which is provided so as to be closed near the distal end of the first portion 301 and open at the bottom of the flange portion 3013. The positional relationship (distance t) between the distal end of the blind hole 3014 and the top of the conical tip is such that the tip of the soft tennis ball 1 is shaved off in a surface polishing step after molding and vulcanization (normally). Shaving dimensions are 0.5mm
The degree is set so that the blind hole 3014 has a dimensional relationship in which the blind hole 3014 opens to the outside of the ball. The reason why the inclination angle of the above-mentioned substantially conical tip portion 3011 is changed in the middle is that the rubber plug 3 is attached to an unvulcanized spherical shell forming member 4 described later.
This is to ensure that the tip of the blind hole 3014 can be arranged as close as possible to the top of the conical tip while ensuring that the operation of pushing in is smoothly performed.

The solid column-shaped second portion 302 is provided with a slit 3021. One end of the slit 3021 faces the blind hole 3014, and the other end is opened at the rear end of the solid column. 302
Reference numeral 2 denotes a hole at the rear end of the slit.

The check valve 303, which is a valve member,
As shown in the figure, a sleeve-shaped body portion 3031 fitted on the outer periphery of the columnar portion 302 having a circular cross section, and a slit 3034
And a lip 3032 that forms the body portion 3 via four arcuate surfaces 3033 (a wide surface of the strip and surfaces continuous with both side edges of the strip).
031, and the trunk portion 3031 is fitted to the columnar portion 302 and adhered and fixed to be integrated with the rubber stopper.

Preferred examples of the rubber stopper 3 configured as described above are as follows.

Air injection valve mechanism 3 Total weight: 0.8 g or less Rubber stopper first part 301 Natural rubber vulcanized product Hardness: 40 to 70, weight: 0.1 to 0.2 g First part 301 Overall height: 2. 0 to 2.5 mm Tip 3011 Hem diameter: 9 to 12 mmφ, Tip angle: 100 to 150 ° Angle below the angle change point (0.3 to 0.7 mm from the tip): Less than 90 to 60 ° Blind hole 3014 Diameter: 0.6-1.2 mmφ, Height: 1.7-2.3 mm Rubber stopper second part 302 Natural rubber vulcanized product Hardness: 20-35, Weight: 0.2-0.3 g Diameter: 6 ８8 mmφ, height: 6-7 mm Slit across upper and lower ends in the center Check valve 303 Natural rubber vulcanized product Hardness: 20-50, weight: 0.2-0.3 g Total length: 20-25 mm As above Air injection valve mechanism 3 (the color of the rubber stopper is different from the ball shell) 4), as shown in FIG. 4, by performing a work of pushing a sharp tip from the back surface (the inner surface of the spherical shell) when the ball 1 is formed into the unvulcanized spherical shell forming member 4. The sharp tip is embedded so as to reach the surface (outer surface of the spherical shell) of the unvulcanized spherical shell forming member 4. At this time, the surface of the tip portion 3011 of the rubber stopper and the flange portion 3
An adhesive is applied to the surface of the ball-shaped member No. 013 which is in contact with the ball-shell forming member 4 so that the ball-shell is firmly adhered and fixed at the time of forming and vulcanizing the ball. As the adhesive used at this time, the adhesive used for bonding a conventional navel member can be preferably used, but is not particularly limited to this. The unvulcanized spherical shell forming member 4 is defined as
For example, as an example, it means a combination (not shown) of a cylindrical part for forming a ball and a pair of lid-like parts for closing an opening thereof, which have been conventionally performed, and an air injection valve mechanism. Incorporating 3 may be in any of the three pieces.

Thereafter, the unvulcanized spherical shell forming member 4 of the three pieces is placed in a mold in a predetermined state, and a process of forming and vulcanizing the soft tennis ball 1 is performed. This machining operation can be performed as before.

The ball formed and vulcanized in the manner described above has a split-type streak and the like on the ball surface (outer surface), and does not have a surface suitable for the soft tennis ball 1 because it has no surface. Polishing is performed to polish the surface according to the method. By the surface polishing by this polishing, the entire surface of the ball spherical shell is polished, and the tip of the rubber plug of the air injection valve mechanism incorporated so as to reach a part of the surface is scraped off. That is, as shown in FIG. 5, the opening of the closed end on the distal end side of the blind hole 3014 (see FIG. 4) that is closed before polishing is exposed to the ball surface.

As shown in FIG. 6, the soft tennis ball 1 of the present embodiment manufactured as described above has a rubber plug having a color tone different from that of the spherical shell 2 of the ball body on a part of the surface of the soft tennis ball 1. Since the blind hole 3014 which is exposed or at least opened by the processing of the rubber stopper is conspicuous, the second part (column-shaped part) 3 which is a navel easily for the user.
It is possible to know the position of No. 02, and it is possible to obtain an advantage that it is possible to omit the conventional manual operation of marking a symbol for indicating the navel portion without increasing the work load in the ball manufacturing process.

Next, the operation of injecting air through the air injection valve mechanism 3 configured as described above will be described.

The air injection valve mechanism 3 of this embodiment has a blind hole (cylindrical portion) 30 at the tip of the first portion 301 exposed on the ball surface.
14, an air injection jig 5 having a round insertion rod 501 shown in FIG. 10 is inserted as shown in FIG. 7, and a check valve 303 is inserted through a hole 3022 at the rear end of the second portion of the rubber stopper 302. Project inside. As a result, the air outflow hole 502 at the tip of the insertion rod 501 is located in the space inside the check valve 303, and the rubber pump 503 of the jig 5 is compressed by closing the hole formed therein with a finger. The pressurized air is sent from the air outflow hole 502 into the check valve 303, and the air in the check valve 303, which has a pressure higher than the ball internal pressure, opens the slit 3034 of the check valve 303 and enters the ball. Press-fit. If the air injection into the ball is insufficient by one operation, release the finger closing the hole of the rubber pump 503 of the jig 5 to restore the rubber pump, and close the hole again with the finger to compress and inject the air. Operation to perform the operation. The rubber pump 503
When is restored, the check valve 303 prevents air from flowing in the reverse direction, so that the air in the ball does not leak outside. After injecting air to a predetermined pressure, the jig 5 is pulled out and the air injecting operation is completed.

The air injected into the ball as described above is vented from the outside to the inside of the ball by the check valve 303, but is prevented from venting in the opposite direction. Air leaks through are reliably prevented.

In addition, the air injection valve mechanism 3 having such a configuration
Does not require strong tightening force, etc., it only requires the work of fitting a non-return valve to a rubber stopper and adhesively fixing it, making the manufacturing operation simple and making the mechanism lightweight. There is an advantage that can be. Further, the valve mechanism 3 fitted with the check valve includes a ball spherical shell forming member 4 in an unvulcanized state.
The rubber plug can be installed at a predetermined position on the ball shell just by pushing it into the ball shell.
Excellent productivity can be secured.

Embodiment 2 In this embodiment shown in FIGS. 8 and 9, a flexible film-like bag 6 having a ventilation opening 601 is used instead of the check valve 303.
This shows an example in which is used as a substantially one-way breathable valve member because of the relationship between the flexibility of the film and the ball internal pressure.

That is, the film-like bag body 6 of the present embodiment is in the form of a finger-sack type bag, and the open end 602 is adhesively fixed to the outer periphery of the column of the rubber stopper second portion 302 so that the closed end is formed. Are fitted to the rear end of the columnar portion (see FIG. 8). The ventilation opening 601 is formed in the bag body 6 so as to be eccentric with respect to the rubber stopper second portion 302.

The operation of injecting air through the air injection valve mechanism 3 having the bag 6 having such a configuration will be described.

In this example, the operation of inserting the insertion rod 501 of the air injection jig 5 shown in FIG. 10 is the same as in the first embodiment. When the air injection operation is similarly performed in a state where the jig 5 is inserted, the bag body 6 is inflated by the injected high-pressure air (see FIG. 9), and the injected air passes through the ventilation opening 601 and is injected into the ball. Ventilated.

On the other hand, when the insertion rod 501 of the air injection jig 5 is not inserted or when the jig is pulled out, the bag 6 is easily crushed by the internal pressure of the ball, and the ventilation opening 601 is formed of rubber. Since it is in close contact with the rear end of the plug second portion 302, ventilation through this opening is substantially prevented. Therefore, also in the present embodiment, a substantially one-way breathable valve mechanism is configured, and the problem that the internal pressure of the ball leaks to the outside is prevented.

In the case of this embodiment, the film-shaped bag needs only to have the above-mentioned predetermined heat resistance and the strength not to be mechanically damaged, and the valve based on its own structure is sufficient. Since there is no need to provide a function, there is an advantage that the weight can be made lighter than that of the first embodiment.

[0038]

According to the first aspect of the present invention, there is provided an insertion hole, such as a slit, which is inserted into and out of the ball for inserting an air injection jig having a rounded tip. Without strongly tightening the slits, etc.
Since air leakage can be prevented by a one-way air-permeable lightweight valve mechanism, air leakage can be reliably prevented, and production is easy because no tightening ring is used.

Further, since air injection can be performed using a jig having a rounded tip, there is no danger that a needle sticks to a portion other than the navel, which may cause a fatal defect of the soft tennis ball.
Also, there is no danger of sticking a finger with a needle.

According to the second aspect of the present invention, a flexible film bag is used. The bag is easily crushed by the internal pressure of the ball and closely adheres to the other end of the rubber plug to prevent air leakage. When is injected, it inflates to effectively function as a valve mechanism, and can satisfy the extremely lightweight one-way air-permeable function. Further, according to the invention of claim 4, one end is provided in a circular opening shape (sleeve shape) fitted to the other end of the rubber stopper, and the other end is provided in a flat strip shape having a slit for air outflow. The structure of the valve member itself constitutes a valve having one-way air permeability (check valve).

According to the manufacturing method of the sixth aspect, a rubber plug having a wedge-shaped tip is pressed into an unvulcanized spherical shell forming member from the inner side without drilling a spherical shell. The rubber stopper can be assembled at a predetermined position only by the operation, and the other parts can be manufactured in the same manner as the molding, vulcanizing and polishing steps in the conventional manufacturing of soft tennis balls. The conventional manual process of marking is not required, and the productivity is improved. In addition, the opening of the cylindrical portion exposed on the ball surface serves as a mark for inserting an air injection jig having a rounded tip, so that the air injection operation is facilitated.
Further, the rubber stopper may have the same color as the spherical shell of the soft tennis ball body, but it is more preferable to use a rubber stopper having a different color tone so that the user can clearly indicate the air injection position.

[Brief description of the drawings]

FIG. 1 is a view for explaining a structure of a valve constituting an air injection portion of a soft tennis ball according to a first embodiment of the present invention.

FIG. 2 is a development view of members constituting the rubber stopper of FIG.

FIGS. 3A and 3B are diagrams for explaining the structure of a check valve assembled to a rubber stopper, wherein FIG. 3A is a front view and FIG. 3B is a bottom view.

FIG. 4 is a partial cross-sectional view of a ball before polishing, in which a soft tennis ball is formed and vulcanized by incorporating the valve of FIG. 1;

FIG. 5 is a partial cross-sectional view of the ball shown in FIG. 4 after the surface (outer surface) of the ball has been polished.

FIG. 6 is a perspective view of the soft tennis ball of the present invention.

FIG. 7 is a view showing a state in which the air injection jig of FIG. 10 is inserted into the air injection section of the first embodiment.

FIG. 8 is a view for explaining a structure of a valve constituting an air injection portion of the soft tennis ball according to the second embodiment of the present invention.

FIG. 9 is a view showing a state in which the air injection jig of FIG. 10 is inserted into the air injection section of the second embodiment.

FIG. 10 is a front view of a jig used for injecting air into the soft tennis ball of the present invention.

FIG. 11 is a front view of a conventional jig used for injecting air into a soft tennis ball.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Soft tennis ball 2 ... Ball ball shell 3 ... Air injection valve mechanism 301 ... First part 3011 ... Tip part 3012 ... Angle change point of slope 3013 ... Flange part 3014 ... blind hole 302 ... second part 3021 ... slit 3022 ... hole 303 ... check valve 3031 ... body part 3032 ... lip 3033 ... arcuate surface 3034 ...・ Slit 4 ・ ・ ・ Unvulcanized spherical shell forming member 5 ・ ・ ・ Air injection jig 501 ・ ・ ・ Plug rod 502 ・ ・ ・ Air outlet hole 503 ・ ・ ・ Rubber pump 6 ・ ・ ・ Bag 601 ・ ・ ・Ventilation opening 602: open end 7: injection needle type air injection jig 701: needle 702: rubber pump

Claims (6)

[Claims] 1. A soft tennis ball provided with an air injection valve mechanism for injecting air into the inside of a ball at a part of the ball shell, wherein the air injection valve mechanism has one end on the surface of the ball shell. And is fixed to the ball shell with the other end protruding into the ball, and a through hole extending across the both ends so that a rod-shaped air injection jig can be inserted from the outside of the ball to the inside of the ball. And a rubber plug having the rubber plug and the other end of the insertion hole covered by the rubber plug so that air injected by the air injection jig inserted into the insertion hole can flow into the ball. But a one-way permeable valve member for preventing air in the ball from venting to the hole at the other end of the rubber plug. 2. The valve member is easily crushed by the internal pressure of the ball and is in close contact with the other end of the rubber plug, and is near the other end when air is injected by an air injection jig inserted into the insertion hole. A flexible film bag that swells so as to form a space, an opening for ventilation is provided in a part of the bag, and the collapse of the bag causes a hole at the other end of the rubber stopper to be formed. 2. The space between the bag and the opening is sealed.
Soft tennis ball as described in. 3. The bag according to claim 2, wherein the opening of the bag is displaced so as not to overlap with the hole at the other end of the rubber stopper when the bag is crushed. Soft tennis ball. 4. The valve member according to claim 1, wherein one end is provided in a circular opening shape fitted to the other end of the rubber stopper, and the other end is provided in a flat strip shape having a slit for air outflow. The soft tennis ball according to claim 1, wherein 5. The insertion hole of the rubber plug is formed by connecting the cylindrical hole at one end provided to open to the surface of the ball shell and the slit provided at the other end. The soft tennis ball according to any one of claims 1 to 4, wherein 6. The soft tennis ball according to claim 1, wherein the rubber stopper has a tip tapered toward the one end.